TABLE 2.

Kinetic parameters of DadD and mutants with 5′-dA, MTA, SAH, and Ad

DadD	Substrate	Mean Km (mM) ± SD	kcat (s−1)	kcat/Km (M−1 s−1)
WT	5′-dA	0.014 ± 0.0012	1.2 × 105	9.1 × 109
	MTA	0.11 ± 0.028	1.6 × 102	1.1 × 106
	SAH	1.1 ± 1.3	1.3 × 103	4.4 × 106
	Ad	0.15 ± 0.0047	1.1 × 102	7.5 × 105
Y136R	5′-dA	0.032 ± 0.033	3.3 × 102	1.7 × 107
	MTA	0.022 ± 0.0019	2.2 × 102	1.1 × 107
	SAH	0.16 ± 0.13	24.7	2.3 × 105
	Ad	0.072 ± 0.0018	1.4 × 102	2.9 × 106
E150R	5′-dA	0.021 ± 0.0061	2.1 × 102	9.8 × 107
	MTA	0.048 ± 0.0029	2.0 × 102	4.2 × 106
	SAH	3.9 ± 5.2	58.2	2.1 × 104
	Ad	0.15 ± 0.047	1.1 × 102	7.5 × 105
Y136R/E150R	5′-dA	0.05 ± 0.046	1.12	3.1 × 104
	MTA	0.073 ± 0.0054	1.39	1.9 × 104
	SAH	0.4 ± 0.1	2.41	5.3 × 103
	Ad	NMa	NM	NM

^aNM, not measurable.